1. Field of the Invention
The invention relates to an actuator system having at least one arrangement for an electrical plug, the arrangement including a socket and a rotatable union nut in connection with this, the union nut having an opening for inserting the plug into the socket.
2. The Prior Art
Low voltage plug connections are widely used in conjunction with apparatus, equipment and installations, and are well-known. As examples of plugs which are typically used for adjustable pieces of furniture with actuator systems, the conventional Jack or DIN types and the more modern Minifit type (trademark of Molex corp.) can be mentioned. The plugs are normally only fixed in the connection by the clamp connectors of the socket. A plug may therefore be inserted relatively easy into the socket, but it also has the disadvantage that it may unintentionally fall out, either completely or partially. This may e.g. happen when the bed is transported over an uneven surface, or when the cord gets caught in something. Sometimes it is desirable and at times required that a plug cannot readily be removed. If it is an electrically adjustable bed, it is very inconvenient for both the user of the bed and for the nursing staff when a plug falls out, as the bed then loses some of its functionalities e.g. that the resting surface of the bed cannot be adjusted. This also causes an extra strain on the service staff who have to solve the problem. At worst, it could be fatal e.g. when the bed with a patient who is in shock cannot be adjusted to a horizontal resting surface. If a plug is not secured in its socket in the housing, there is the further risk that water and disinfectants may penetrate into the housing during cleaning and cause damage to electronics and plug connections. Perhaps the damage does not appear right away, but can later on develop into e.g. inexplicable interruptions or break-down of the control unit.
EP 0 660 452 to LINAK A/S discloses a union nut having locking means for a plug, where the union nut is divided into two parts, where the first part forms an almost closed circle, and a second part serves to close the circle and surround the plug and lock this against a locking pin on the housing. The solution is usable, but nevertheless not quite practical, as the union nut has to be mounted after the insertion of the plug into the socket and is thereupon locked by inserting the locking means. As the mounting of cables is often carried out when the control unit or the actuator is mounted on the piece of furniture, it causes a good deal of time-consuming inconvenience. Further, there is a possibility that the many components may disappear, causing them not to be mounted, which results in the known disadvantages.
The object of the invention is to provide a simple solution to the outlined problem.